patch 7.4.1476
Problem:    Function arguments marked as unused while they are not.
Solution:   Remove UNUSED. (Yegappan Lakshmanan)
diff --git a/src/ex_cmds2.c b/src/ex_cmds2.c
index 88257cc..e1a0dfd 100644
--- a/src/ex_cmds2.c
+++ b/src/ex_cmds2.c
@@ -2033,7 +2033,7 @@
     static int
 do_arglist(
     char_u	*str,
-    int		what UNUSED,
+    int		what,
     int		after UNUSED)		/* 0 means before first one */
 {
     garray_T	new_ga;